Abstract
Although the literature on human resource management (HRM) has provided compelling evidence that certain HRM practices can help employees attain the competence and confidence to carry out their role, less is known about the potential impact of HRM practices on volunteers in the context of non-profit organisations. This study addresses this gap by presenting a model that situates role mastery – operationalised as role clarity and self-efficacy – as its centrepiece. Our model suggests that role mastery leads to commitment to the volunteer organisation and that role mastery can be achieved through training and supportive relationships with paid staff. A dual-mediation analysis of survey data from a humanitarian non-profit organisation in the UK (n = 647) supported our theoretical model. We contribute to volunteering theory and practice by identifying tools that non-profit organisations can employ to maximise the role mastery and commitment of volunteers.